Mannich reaction products of high molecular weight alkyl phenols, aldehydes and polyaminopolyalkyleneamines



United States Patent lice 3,413,347, Patented Nov. 26, 1968 ABSTRACT OFTHE DISCLOSURE Reaction products of high molecular weight alkylphenols,aldehydes and N,N-dia1kyl, hydroxyalkyl or aminoalkyl-alkylene diaminesare ashless dispersants for lubricating oils.

This invention relates to an ashless lubricating oil dispersant. Inparticular, this invention relates to the condensation products of analkylphenol, an aldehyde and a diamine and to improve lubricating oilcompositions containing this condensation product.

A large percentage of todays automobiles are used in city stop-and-godriving Where the engines do not reach their most efficient operatingtemperatures. Large amounts of partial oxidation products are formed andreach the crankcase of the engine by blowing past the piston rings.These partial oxidation products react with oil in the crankcase andlead to the formation of deposits on various operating parts of engines,resulting in sludge and varnish. Other deposits and organic acids resultfrom deterioration of the oil itself. To prevent deposition of thesematerials on various engine parts, it is necessary to incorporatedispersants in the lubricating oil compositions, thus keeping thesepolymeric products highly dispersed in a condition unfavorable fordeposition on metals.

For the most part, the various dispersants which have been used toeffectively disperse the precursors of sludges and varnishes are metalorganic compounds, particularly those compounds wherein the metal islinked to an organic group through an oxygen atom. These dispersantsalso neutralize to some extent the organic acids, and thereby helpprevent corrosion of the engine parts. However, such dispersants havethe disadvantage of forming ash deposits in the engine, which depositslower engine performance by fouling the spark plugs and valves and bycontributing to preignition. Therefore, a need exists for a dispersantthat effects the removal of sludge and varnish from internal combustionengines, but does not form ash deposits in the engine. The presentinvention fulfills this need.

It is an object of this invention to supply ashless dispersants. Afurther object is to supply ashless dispersants of superior dispersantpower by condensing an alkylphenol with an aldehyde and a diamine. Astill further object is to supply lubricating oil compositions of highdispersancy.

These and other objects are accomplished by providing a dispersant madeby (A) condensing an alkylphenol having the formula:

wherein R is an alkyl radical having an average molecular weight of from550 to 1400, with (B) an aldehyde having the formula:

wherein R is hydrogen or an alkyl radical containing from 1 to 6 carbonatoms, and (C) a diamine compound having the formula:

(III) wherein R is a divalent alkylene radical containing from 1 to 6carbon atoms, and R and R are selected from the group consisting ofalkyl radicals containing 1 to 6 carbon atoms and radicals having theformula:

wherein R is a divalent alkylene radical containing from 1 to 6 carbonatoms and X is selected from thegroup consisting of the hydroxyl radicaland the amine radical.

In a preferred embodiment the aldehyde used in the above condensationreaction is formaldehyde. In a still further preferred embodiment thediamine reactant represented by above Formula III isN,N-dimethyl-1,3-propanediamine.

The alkylphenol reactant represented by Formula I is an alkylphenolwherein the alkyl radical has an average molecular weight of from about550 to 1400. In a more preferred alkylphenol reactant the alkyl radicalhas an average molecular weight of from about 800 to 1300, and in themost preferred alkylphenols the alkyl radical has an average molecularweight of from about 900 to 1100.

Alkylphenols suitable for use in the preparation of the presentdispersants are readily prepared by adaptation of methods well known inthe art. For example, they may be prepared by the acid catalyzedalkylation of phenol with an olefin. In this method, a small amount ofan acid catalyst such as sulfuric or phosphoric acid, or preferably aLewis acid such as BF -etherate, BF -phenate complex or AlCl -HSO isadded to the phenol and the olefin then added to the phenol attemperatures ranging from about 0 up to 200 C. A preferred temperaturerange for this alkylation is from about 25 to 150 C., and the mostpreferred range is from about 50 to C. The alkylation is readily carriedout at atmospheric pressures, but if higher temperatures are employedthe alkylation may be carried out at super atmospheric pressures up toabout 1000 p.s.i.g.

The alkylation of phenols produces a mixture of mono-, diandtri-alkylated phenols. Although the preferred reactants are themono-alkylated phenols represented by Formula I, the alkylation mixturecan be used without removing the higher alkylation products. Thealkylation mixture formed by alkylating phenol with an olefin using anacid catalyst can be merely water washed to remove the unalkylatedphenol and the acid catalyst and then used in the condensation reactionwithout removing the diand tri-alkylated phenol products. Another methodof removing the unreacted phenol is to distill it out, preferably usingsteam distillation or under vacuum, after washing out the alkylationcatalyst. The amount of diand tri-alkylated phenols can be kept at aminimum by restricting the amount of olefin reactant added to thephenol. Good results are obtained when the mole ratio of olefin tophenol is about 0.25 moles of olefin per mole of phenol to 1.0 mole ofolefin per mole of phenol. A more preferred ratio is from about 0.33 to0.9, and a most preferred ratio is from about 0.5 to 0.67 moles ofolefin per mole of phenol.

The olefin reactant used to alkylate the phenol is preferably amonoolefin with an average molecular weight of from about 550 to 1400.The more preferred olefins are those formed from the polymerization oflow molecular weight olefins containing from about 2 to 10 carbon atoms,such as ethylene, propylene, butylene, pentene and decene. A mostpreferred olefin is that made by the polymerization of butene to producea polybutene mixture with an average molecular weight of from about900-1100.

The aldehyde reactant represented by Formula II preferably contains from1 to 7 carbon atoms. Examples are formaldehyde, acetaldehyde,propionaldehyde, butyraldehyde, valeraldehyde, hexaldehyde andheptaldehyde. The more preferred aldehyde reactants are the lowmolecular weight aliphatic aldehydes containing from 1 to about 4 carbonatoms such as formaldehyde, acetaldehyde, butyraldehyde andisobutyraldehyde. The most preferred alde hyde reactant is formaldehyde,which may be used in its monomeric or its polymeric form such aspara-formaldehyde.

The diamine reactant is a diamine having Formula III wherein R is adialkylene radical containing from 1 to 6 carbon atoms and R and R areeither alkyl radicals containing 1 to 6 carbon atoms or radicalsrepresented by Formula IV wherein R is a divalent alkylene radicalcontaining from 1 to 6 carbon atoms and X is a hydroxyl or amineradical. The term divalent alkylene radical as used in describing thepresent invention means a divalent hydrocarbon radical having theempirical formula C H wherein n is an integer of from 1 to 6. Thepreferred diamine reactants are those in which R is a .low molecularweight alkylene radical containing from 1 to about 4 carbon atoms suchas the CH C H --C H or C H radicals. The two amine groups of the diaminereactant may be bonded to the same carbon atom, adjacent carbon atoms orto carbon atoms removed from each other by one or more interveningcarbon atoms. Some examples of diamine reactants wherein the aminegroups are attached to the same carbon atoms of the alkylene radical Rare N,N-dialkyl-methylenediamine, N,N- dialkanol-1,3-ethanediamine, andN,N-di(aminoalky1)- 2,2-propanediamine.

Some examples of diamine reactants in which the amine groups are bondedto adjacent carbon atoms of the R alkylene radical areN,N-dialkyl-1,Z-ethanediamine, N,N- dialkanol-l,2-propanediamine,N,N-di(aminoalkyl) 2,3- butanediamine, andN,N-dialkyl-2,3(4-methylpentane) diamine.

Some examples of diamine reactants in which the amine groups are bondedto carbon atoms on the alkylene radical represented by R which areremoved from each other by one or more intervening carbon atoms areN,N-dialkyl- 1,3-propanediamine, N,N dialkanol-1,3-butanediamine,N,N-di(aminoalkyl)-1,4-butanediamine, and N,N-dialkyl-1,3-hexanediamine.

As previously stated, R and R are alkyl radicals containing 1 to 6carbon atoms or alkyl radicals containing 1 to 6 carbon atoms which aresubstituted with the hydroxyl or amine radical. Some examples ofhydroxyl substituted radicals are 2-hydroxy-n-propyl, Z-hydroxyethyl,2-hydroxy-n-hexyl, 3-hydroxy n propyl, 4-hydroxy-3- ethyl-n-butyl, andthe like. Some examples of amine substituted R and R radicals are2-aminoethyl, 2-amino-npropyl, 4-amino-nbutyl,4-amino-3,3-dimethyl-n-butyl, fi-amino-n-hexyl, and the like. PreferredR and R radicals are unsubstituted alkyl radicals such as methyl, ethyl,n-propyl, isopropyl, sec-butyl, n-amyl, n-hexyl, Z-methyln-pentyl, andthe like. The most preferred R and R substituents are methyl radicals.

Some specific examples of diamine reactants are:

N,N-dimethyl-1,3-propanediamine;

N,N-dibutyl-1,3-propanediamine;

N,N-dihexyl- 1,3 -prop anediamine;

N,N-dimethyl-1,2-propanediamine;

N,N-dimethyl-1, l-propanediamine N,N-dimethyl-1, 3-hexanediamine;

N,N-dimethyl-1,3-butanediamine;

N,N-di( 2-hydroxyethyl) 1 ,3-prop anedia mine;

N,N-di(2-hydroxybutyl)-1 ,3-propanediarnine;

N,N-di(6-hydroxyhexyl)-1,l-hexanediamine;

N,N-di(2-aminoethyl)-1,3-propanediamine;

N,N-di(2-amino-n-hexyl -1,2-butanediamine;

N,N-di(4-amino-3,3-dimethyl-n-butyl -4-methy1- l ,3-

pentanediamine;

N- (Z-hydroxyethyl -N- (Z-aminoethyl -1,3 -prop anediamine.

The condensation products are easily prepared by mixing together thealkylphenol, the aldehyde reactant and the diamine reactant, and heatingthem to a temperature sufficient to cause the reaction to occur. Thereaction may be carried out without any solvent, but the use of asolvent is usually preferred. Preferred solvents are the waterimmiscible solvents including water insoluble alcohols (e.g., amylalcohol) and hydrocarbons. The more preferred water immiscible solventsare hydrocarbon solvents boiling from 50 to about 200 C. Highlypreferred solvents are the aromatic hydrocarbon solvents such asbenzene, toluene, xylene, and the like. Of these, the most preferredsolvent is toluene. The amount of solvent employed is not critical. Goodresults are obtained when from one to about 50 percent of the reactionmass is solvent. A more preferred quantity is from 3 to about 25percent, and a most preferred quantity of solvent is from 5 to 10percent.

The ratio of reactants can vary from about l5 moles of alkylphenol to 15moles of aldehyde reactant to 1-3 moles of diamine reactant. A morepreferred reactant ratio is 1.5-2.5 moles of alkylphenol to 2.54 molesof aldehyde to 1.5-2.5 moles of diamine reactant. A most preferred ratioof reactants is about 2 moles of alkylphenol to about 3 moles ofaldehyde to about 2 moles of diamine reactant.

The condensation reaction will occur by simply warming the reactantmixture to a temperature sufficient to effect the reaction. The reactionwill proceed at temperatures ranging from about 50 to 200 C. A morepreferred temperature range is from about 75 to 175 C. When a solvent isemployed it is desirable to conduct the reaction at the refluxtemperature of the solvent-containing reaction mass. For example, whentoluene is used as the solvent, the condensation proceeds at about to C.as the water formed in the reaction is removed. The water formed in thereaction co-distills together with the water immiscible solvent,permitting its removal from the reaction zone. During this water removalportion of the reaction period the water immiscible solvent is returnedto the reaction zone after separating water from it.

The time required to complete the reaction depends upon the reactantsemployed and the reaction temperature used. Under most conditions thereaction is complete in from about one to 8 hours.

The reaction product is a viscous oil and is usually diluted with aneutral oil to aid in handling. A particularly useful mixture is abouttwo-thirds condensation product and one-third neutral oil.

The following examples will serve to illustrate the condensationreaction. All parts are parts by weight unless otherwise indicated.

Example 1 To a reaction vessel equipped with a stirrer, condenser andthermometer was added 363 parts of polybutene having an averagemolecular weight of 1100 and 94 parts.

of phenol. Over a period of 3 hours, 14.2 parts of a 48 percent BF-etherate complex was added while maintaining the reaction temperaturebetween 50 and 60 C. The reaction mixture was then stirred at 5560 C.for an additional 4.5 hours and then transferred to a second reactionvessel containing 750 parts of water. The aqueous phase was removed andthe organic phase washed 4 times with 250 parts of water at 60 C.,removing the aqueous phase after each wash. The organic product was thendiluted with about 200 parts of n-hexane and dried with anhydrous sodiumsulfate. The product was then filtered and the hexane and othervolatiles removed by vacuum distillation until the product remaining wasat 75 C. at 0.3 mm. Hg. As a reaction product, there was obtained 368.9parts of an alkylphenol as a viscous ambercolored oil having an averagemolecular weight of 810.

In a separate reaction vessel was placed 267 parts of the alkylphenolprepared above, 33.6 parts of N,N-dimethyl-1,3-propanediamine and 330parts of isopropanol. While stirring, 15.8 parts of 95 percentpara-formaldehyde was added. The reaction mixture was then refluxed for6.5 hours. Following this, the solvent and other volatiles weredistilled out to a reaction mass temperature of 115 C. at about mm. Hg.The reaction product was a viscous amber-colored liquid having excellentdispersancy eifect in hydrocarbon lubricating oils.

Example 2 To a reaction vessel equipped with a stirrer, condenser andthermometer was added 934 parts of a polybutene having an averagemolecular weight of about 900, 196 parts of phenol and 22 parts of a BF-ether complex containing 48 percent BF The temperature was raised to 60C. and maintained there for 3 hours, following which 120 parts of waterwere added. Steam was then injected into the reaction mass, causing theunalkylated phenol to distill out. The steam distillation was continueduntil almost all the phenol had been removed. About 870 parts of toluenewere then added and the organic phase sepa rated and dried overanhydrous sodium sulfate. The toluene was then remove by vacuumdistillation until the alkylated phenol reached a temperature of 145 C.at a pressure of 0.2 mm. Hg. Infrared analysis for hydroxyl contentshowed that the product had an average molecular weight of 1060. v

To a second reaction vessel equipped with stirrer, condenser andthermometer was added 313 parts of the alkylphenol prepared above, 30.1parts of N,N-dimethyl-1,3- propanediamine, 14 parts of 95 percentpara-formaldehyde and 152 parts of toluene. While stirring, the reactiontemperature was raised gradually to 145 C. over a 2.5 hour period. Waterwas separated from the toluene that distilled out and the toluenedistillate was returned to the reaction zone. The volatile material inthe reaction product was then removed by maintaining the product atabout 140-145 C. while reducing the pressure in the reaction system toabout 12 mm. Hg. The volatiles that distilled out during this periodwere condensed and removed from the reaction mass, resulting in 352parts of the condensation product in the form of a viscous oil.

Example 3 To a reaction vessel equipped as in Example 1 was added 260parts of isopropyl alcohol, 266 parts (0.33 mole) of the alkylphenolprepared as described in Example 1 and 45 parts (0.33 mole) ofN,N-di(2-hydroxyethyl)-1,3-propanediamine. While stirring, 15.8 parts(0.5 mole) of 95 percent para-formaldehyde were added. The reactionmixture was stirred at reflux for 6.5 hours, following which the solventand volatiles were distilled out to a liquid temperature of 115 C. at 15mm. Hg, leaving a viscous oil soluble residue.

Example 4 To a reaction vessel equipped with stirrer, thermometer andcondenser is added 3000 parts of an alkylated phenol with an averagemolecular weight of 1500. The phenol is primarily mono-alkylated, butsmall amounts of diand some tri-alkylphenols are present. Followingthis, parts of para-formaldehyde, 204 parts ofN,N-dimethyl-1,3-propanediamine and 200 parts of toluene are added.While stirring, the temperature is raised to C. Toluene distillstogether with some water. The water is removed from the toluenedistillate and the toluene returned to the reaction zone. Over a 4 hourperiod, during which time water is continuously removed, the reactiontemperature rises to about C. Following this, the toluene and othervolatile material is removed by reducing the pressure in the system toabout one mm. Hg, while maintaining the temperature at about C. andallowing the volatiles to distill out. The resultant product is anashless lubricant dispersant.

Example 5 To the reaction vessel of Example 3 is added 2000 parts of aprimarily monoalkyl phenol having an average molecular weight of about800, 150 parts of para-formaldehyde, 324 parts ofN,N-di-(2-hydroxyethyl)1,3-propanediamine and 200 parts of toluene.While stirring, the reaction temperature is raised to 100 C. over a 0.5hour period, and then to 140 C. over a 4 hour period. During the timefrom 100 to 140 C., the water that codistills with the toluene isremoved and the toluene returned to the reaction zone. Following this,the volatiles are removed by vacuum distillation to a producttemperature of 150 C. at about one mm. Hg. The resultant product is anashless lubricant dispersant.

Example 6 To a reaction vessel as described in Example 2 is added 1.75mole parts of a primarily monoalkylated phenol with an average molecularweight of about 1200. Following this, there is added 300 parts oftoluene, 90 parts of para-formaldehyde and 2.0 mole parts of N,N-di(2-aminoethyl)-1,3-propanediamine. The temperature is raised to 100 C. overa 0.5 hour period and then slowly to 150 C. during the next 3 hours.Water co-distills with the toluene and is removed and the toluenereturned to the reaction Zone. Following this, the volatiles are removedby vacuum distillation until the reaction mass is at a temperature of150 C. at about one mm. Hg. The product is an ashless lubricantdispersant.

The foregoing examples serve only to demonstrate some of the methods ofpreparing the product and not to limit the invention to the reactants orreactant ratios shown. Any of the previously described reactants may beused in the process in the ratios previously set forth.

The dispersants of this invention are effective in both hydrocarbon andsynthetic lubricating oils including lubricating oils used in sparkignition engines and diesel engines. To prepare oil compositions of thisinvention, from about 0.01 to about 10 weight percent, and preferablyfrom 1 to 5 weight percent, of a dispersant product of this invention isblended with the base oil. Suitable base oils include petroleum derivedhydrocarbon mineral oils and synthetic oils such as sebacates, adipates,silicone, halogen containing organic compounds such as thefluorohydrocarbons, etc., polyalkylene' glycol lubricants and organicphosphates. The oils may contain other additives including antioxidantssuch as 4,4-methylenebis (2,6-di-tert-butylphenol), zincdithiophosphate, etc., VI improvers, such as the polymethacrylates,corrosion inhibitors such as the calcium sulfonates, antifoam agents,and the like.

The following examples illustrate some of the improved lubricantcompositions of this invention.

Example 7 Lubricants are prepared by blending a solvent refinedhydrocarbon lubricating oil having a viscosity index of 95 and an SAEviscosity of 10 with 0.5 weight percent of4,4'-methylenebis(2,6-di-tert-butylphenyl) 0.4 weight percentdialkyl-hydrogen phosphite, 0.1 weight percent of the N-octylamine saltof l-(octyl)--oxo-3-pyrrolidinecarboxylate and adding the followingconcentration of the indicated dispersant.

Example 8 Synthetic lubricating oils are prepared as in Example 7 byblending the following oils with 3.0 weight percent of the product fromExample 2.

A. A dioctyl sebacate having a viscosity at 210 F. of 36.7 SUS, aviscosity index of 159 and a molecular weight of 426.7.

B. A di-(sec-amyl) sebacate having a viscosity at 210 F. of 33.8 SUS, aviscosity index of 133 and a molecular weight of 342.5.

C. A di-(Z-ethylhexyl) sebacate having a viscosity at 210 F. of 37.3SUS, a viscosity index of 152 and a molecular weight of 426.7.

D. A di-(Z-ethylhexyl) adipate having a viscosity at 210 F. of 34.2 SUS,a viscosity index of 121 and a molecular weight of 370.6.

E. A diisooctyl azelate having a kinematic viscosity of 3.34 centistokesat -65 F., an ASTM slope from 40 F. to 210 F. of 0.693, a pour point of-85 F., a flash point of 425 F. and a specific gravity at C. of 0.9123.

A diisooctyl adipate having a viscosity at 210 F. of 35.4 SUS, aviscosity at 100 F. of 57.3 SUS, a viscosity of 3.980 SUS at F. and aviscosity index of 143.

The reaction products described in this invention are excellentdispersants for lubricating oil. Tests were carried out whichdemonstrate this property.

Sludge dispersancy test In this test, a neutral oil containing thedispersant is first subjected to high temperature oxidation conditionsin a modified Polyveriform Test, as follows. An oil sample is preparedcontaining 0.08 percent zinc as a zinc dithiophosphate, 0.1 percent leadbromide and 5 percent of the test dispersant. A copper-lead bearing isplaced in this test oil and the oil is subjected to a temperature of 300F. for a period of 48 hours, during; which period 48 liters per hour ofair are passed through the oil sample. This treatment measures theability of the test additive to endure under typical engine operatingconditions. Following this, a second test blend is prepared using 10grams of the oil already subjected to the above Polyveriform Test, 83grams of new oil, 7 grams of a typical sludge material and 2 grams ofwater. In this blend, the concentration of the test dispersant carriedover from Polyveriform is reduced to 0.5 percent. This material isemulsified in a blender for 20 minutes and then centrifuged for 2.5hours. Following this, the percent light transmittance of the oil ismeasured. The better the dispersant, the more of the sludge that willremain suspended following the centrifuging, and hence the lower thepercent light transmittance that will be measured. The lighttransmittance of the test oil is compared to the transmittance of thebase oil without sludge. This shows the degree of dispersanteffectiveness. When this test was carried out on a reaction product likethe one prepared in Example 2, the following results were obtained.

As the above test shows, the dispersant of the present inventionretained the sludge in a dispersed form even after 2.5 hours ofcentrifuging to such a degree that only about 1.6 percent as much lighttransmitted through it compared to the light transmitted through the oilWithout dispersed sludge. Engine evaluation This test was a modifiedL-43 low temperature sludge test. The test measures the ability of anoil to control sludge deposits under lower temperature engine operatingconditions. The engine was a single cylinder CLR engine equipped with anew piston, new piston rings, new polished push rods, and newcopper-lead bearings. After one hour break-in, the engine was run underthe following test con ditions.

Speed 1800 r.p.m.

Load Near full throttle. A/F ratio 15.0.

Intake manifold mixture temp. 175 F.

Water in temp. F.

Water out temp F.

Oil gallery temp. F. (approx) Blowby 20 c.f.h.

Intake air humidity 80 grains H O/ lb. air.

Periodic inspections of five critical engine parts for degree of enginedeposits are made at 20 hour intervals. Each test is continued until theoverall sludge rating of the critical parts is 9.0 on a scale in which10 is perfectly clear and 0 is the condition at which the critical partsare completely covered with sludge to a depth of about onequarter inch.The oil used in the test is a typical 10W30 solvent refined commercialbase oil containing 5.5 volume percent of a commercial polymethacrylateVI improver and 0.08 percent zinc as a zinc dithiophosphate. The following table shows the hours to a 9 sludge rating in the engine test attwo different concentrations of the reaction product prepared in ExampleDispersant conc. percent: Hrs. to 9.0 sludge rating The above tableshows the high dispersant effect of the reaction products of the presentinvention in a typical commercial base oil.

I claim:

1. The reaction product of: (A) from 1 to 5 mole parts of an alkylphenolhaving the formula:

wherein R is a branched chain alkyl radical derived from thepolymerization of butane and having an average molecular weight of from800 to 1300, with (B) from 1 to 5 mole parts of an aldehyde having the 910 containing from 1 to 6 carbon atoms and radicals 5. The compound ofclaim 4 wherein said compound having the formula: is the reactionproduct formed by reacting about 2 mole parts of said alkylphenol withabout 3 mole parts of said formaldehyde and about 2 mole parts of saidN,N-diwherein R 1s a divalent alkylene radical contain- 5 h lq 3 i i ingfrom 1 to 6 carbon atoms and X is selected from the group consisting ofthe hydroxyl radi- References Cited cal and the amine radical, saidreaction being UNITED STATES PATENTS carried out at a temperature offrom 50-200 C. 2. The compound of claim 1 wherein said aldehyde is w214591112 1/1949 Obernght' formaldehyde and said diamine is N,N-di(Z-hydroxy- FO G PATE ethyl)'lipmpanedlamme' 771,635 4/1957 GreatBritain.

3. The compound of claim 1 wherein said aldehyde is formaldehyde andwherein said diamine compound is CHARLES R PARKER Primary Examiner.N,N-dimethyl-1,3 -propanediamine. 15

4vThe compound of claim 3 wherein R has an average R. HINES, Examiner.molecular weight of from 900-1100.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.3,413,347 November 26, 1968 Calvin J. Worrel It is certified that errorappears in the above identified patent and that said Letters Patent arehereby corrected as shown below:

Column 8, line 56, "butane" should read butene Signed and sealed thisloth'day of March 1970.

(SEAL) Attest:

Edward M. Fletcher, J r.

Attesting Officer Commissioner of Patents WILLIAM E. SCHUYLER, JR.

